Question

I have seen this statement in many of the documention samples, like here

This class is the default implementation of the “ISomeInterface” interface

what exactly this means ? Thanks

Answer 1

This is somewhat misleading, since an interface, by definition, provides no implementation.

However, many portions of the framework try to make life easier – so they provide a method which takes an interface, but also provides an overload with no parameters. A good example is List<T>.Sort.

The documentation here is suggesting that, if you use a method that would normally require an IComparer<T>, but use it via some overload that doesn’t, you’ll get the referenced "default implementation" used instead.

However, this is really an "implementation detail" of classes unrelated to the interface itself. I personally think this is a poor choice of words in the documentation, and should be something more like:

Many types in the framework rely on a common implementation of this interface provided by
the Comparer class.

This would, in my opinion, provide a more clear meaning to this…